I purchased a cat-back sysytem from rockauto.com, and it was about $120, also has a $75 mail-in rebate. It a good deal, My was the 4.0 engine. It like getting a complete cat-back system for about $40 bucks.

I purchased a cat-back sysytem from rockauto.com, and it was about $120, also has a $75 mail-in rebate. It a good deal, My was the 4.0 engine. It like getting a complete cat-back system for about $40 bucks.

Did you get the SS system? How was it to install? Are the pipes mandrel bent?

dont mean to hyjack, but I was thinking about replacing my muffler with a flowmaster 40 series has anyone ever done this? dose it sound good?

lots of people in the WJ's use them and love them. They are a bit louder then the 70 series though. I know Youtube has some videos up there of a WJ with a 40 series flowmaster on them. But IIRC those were 4.7's.

Recently though there was a discussion on exhausts in the WJ section and someone posted a video of theirs with a 4.0 and Kolaks exhaust on it.Sounded damn good. Link is below

You can do all you want to the exhaust...you aren't going to get better gas milage. I have two 5.2L jeeps and the best they get is 14MPG (average). The AWD and the fact that they have a permanently engaged front axle is why they get horrible gas milage. The magnum engines in any vehicle are not known for fuel economy. If you still need a good inexpensive exhaust, Iron Rock Offroad sells a system that you can pick and choose your components starting around $150.

You can do all you want to the exhaust...you aren't going to get better gas milage. I have two 5.2L jeeps and the best they get is 14MPG (average). The AWD and the fact that they have a permanently engaged front axle is why they get horrible gas milage. The magnum engines in any vehicle are not known for fuel economy. If you still need a good inexpensive exhaust, Iron Rock Offroad sells a system that you can pick and choose your components starting around $150.

Nothing to do with awd. Even if you get a part time tcase, your gas mileage won't go up. Unless of course you've got bad ujoints, bad vc, etc that could be killing the mileage.

However, its all in how you use the skinny pedal. Ive hand calculated(well cell phone) high 16s for the past few tanks. But I have some things to make it breathe better. But that will go down when I get my 4.56s in.

My old 4.0 when stock I got around 21-22 on trips up north, about 140 miles one way, on cruise control 60mph or so.

Gas engines are most efficient cruising(even power), and least when accelerating(changing/using power)
Electrics motors are the direct opposite.